Herbicidal composition

ABSTRACT

The present invention provides a method for post-emergence selective weed control in turf sites by applying an herbicidal composition comprising sulfentrazone and quinclorac to a locus where weeds are present.

This application claims the benefit of U.S. Provisional Application No.61/007,316 filed Dec. 12, 2007.

FIELD OF THE INVENTION

This invention relates to a method for post-emergence selective weedcontrol in turf sites by applying a composition comprising a mixture ofN-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamideand 3,7-dichloro-8-quinolinecarboxylic acid to a locus where weeds arepresent.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 4,497,651 discloses Dichloroquinoline Derivatives for useas Herbicides. U.S. Pat. No. 4,818,275 discloses Herbicidal ArylTriazolinones.

U.S. Pat. No. 6,849,579 discloses and claims a selective synergisticpost-emergent herbicidal composition comprising quinclorac herbicide anda selective protox herbicidal inhibitor in which the composition whenapplied to control unwanted vegetation contains sufficient amounts ofthe quinclorac and the protox inhibitor to supply from about 0.1 toabout 1 lb/acre of quinclorac and from about 0.005 to about 0.06 lb/acreof the protox herbicidal inhibitor.

The use of herbicides to control weeds in turf is well known. There aretwo types of herbicide applications, pre-emergence herbicides preventweed seeds from germinating or emerging and post-emergence herbicidesthat kill emerged and actively growing plants.

Pre-emergence turf herbicides are generally more effective, but must beapplied early in the season before annual weed seeds germinate. In orderto provide season-long control most pre-emergent herbicides need to bereapplied six to eight weeks after the initial application. Aninfestation of annual weeds either over an entire site or in localizedareas of a site cannot be confirmed so early in the season, the time andexpense of treating turf with pre-emergence applications of herbicidesmay not be needed.

Post-emergence turf herbicides are used to control weeds aftergermination and emergence from the soil. The benefit of using apost-emergence turf herbicide for weed control is that it is used onlywhere an infestation is present. Some of the most common post-emergenceturf herbicides must be reapplied several times, for example, organicarsenicals which include MAMA (monosodium methanearsonate), and DSMA(disodium methanearsonate); some need to be applied at a very early weedgrowth stage in order to completely control the infestation, i.e. thefirst to fourth leaf stage, for example, dithiopyr (S,S′-dimethyl2-(difluoromethyl)-4-isobutyl-6-trifluoromethylpyridine-3,5-dicarbothiolate);and others injure or turn turf grasses yellow after application, forexample, fenoxaprop ((+/−)-ethyl2-[4[(6-chloro-2-benzoxaolyl)oxy]phenoxy]propanoate) and quinclorac(3,7-dichloro-8-quinolinecarboxylic acid). Herbicides such as quincloracdo not adequately control crabgrass in the early tiller stage of growth.

It would be most beneficial to provide a post-emergence turf herbicidethat controlled weeds such as crabgrass, clover, nutsedge and violets inone application, at any weed growth stage, and without injury to turfgrasses.

SUMMARY OF THE INVENTION

In accordance with the present invention, it has been found that anherbicidal composition comprising a mixture of sulfentrazone, the commonname forN-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamideand quinclorac, the common name for 3,7-dichloro-8-quinolinecarboxylicacid wherein the composition is present in an herbicidally effectiveamount, has unexpected post-emergence control of certain broadleaf,nutsedge and grass weeds in turf sites.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a method for post-emergence control ofbroadleaf, nutsedge and grass weeds in a turf site, said methodcomprising applying a composition comprising a mixture of sulfentrazoneand quinclorac in a ratio of from 1:5 to 1:1, at a use rate of from0.375 pound of sulfentrazone and quinclorac/acre to 1.5 pounds ofsulfentrazone and quinclorac/acre, provided that the amount ofsulfentrazone applied is equal to at least 0.09 lb/acre.

It has been unexpectedly found that an herbicidal composition comprisinga mixture of sulfentrazone and quinclorac has advantageous properties inselective weed control over the individual components, for example themixture controls post-emergent weeds such as crabgrass, nutsedge,violet, clover, chickweed, sesbania, jimsonweed, kochia, morninggloryand pigweed, at rates which neither component alone can do. A preferredembodiment of this invention is a method for controlling 1 to 5 leaf ortillered crabgrass and nutsedge.

The terms “weed” and “weeds” refer to any unwanted vegetation in turfsites. The terms “turf”, “turf site” and “turf sites” refers to, but isnot limited to, residential and institutional lawns, athletic fields,parks, commercial sod farms and golf course fairways and roughs.

The structural formula of 3,7-dichloro-8-quinolinecarboxylic acid is asfollows:

This material, commonly known as quinclorac, is a post-emergence turfherbicide which controls a number of grass and broadleaf weeds.

The structural formula forN-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamideis as follows:

This material, commonly known as sulfentrazone, is a post-emergence turfherbicide which does not control crabgrass.

In the present invention, the herbicidal composition is a mixture ofsulfentrazone and quinclorac in a ratio of from 1:5 to 1:1, preferablyin a ratio of 1:3. The herbicidal composition of the present inventionis applied at a use rate in which sulfentrazone would be present at aminimum of 0.09 lb/acre. The preferred use rate of the presentherbicidal composition is from 0.375 pound of active ingredients/acre(i.e. a 1:3 ratio would contain 0.09 lb/acre of sulfentrazone and 0.28lb/acre of quinclorac) to 1.5 pounds of active ingredients/acre (i.e. a1:3 ratio would contain 0.375 lb/acre of sulfentrazone and 1.125 lb/acreof quinclorac).

A particular embodiment of the present invention is a method forcontrolling broadleaf, sedge and grass weeds in turf sites whichcomprises applying the present composition of sulfentrazone andquinclorac, either together or sequentially, to a locus where weeds arepresent.

Other herbicides can be employed in conjunction with the first andsecond herbicides described above providing they do not adversely affectthe interaction between the components of this invention. For example itcan sometimes be useful to include additional herbicides to extend therange of activity in order to control a wider spectrum of weeds.

The herbicidal compounds of use in the present invention may be employedin many forms and are often most conveniently prepared in aqueous formimmediately prior to use. One method of preparing such a composition isreferred to as “tank mixing” in which the ingredients in theircommercially available form, either with or without other additives, aremixed together by the user in a quantity of water.

In addition to tank mixing immediately prior to use, the compositioncontaining sulfentrazone and quinclorac may be formulated into a moreconcentrated primary composition which is diluted with water or otherdiluent before use. Such compositions may comprise a surface activeagent in addition to the active ingredients and examples of suchcompositions are set forth below.

The herbicidal compounds of use in the present invention can beformulated as a granule of relatively large particle size for dryapplication to the site where control is desired (for example, 8/16 or4/8 US Mesh), on fertilizer granules, as water-soluble orwater-dispersible granules, as powdery dusts, as wettable powders, asemulsifiable concentrates, as aqueous emulsions, as solutions, or as anyof the other known types of agriculturally-useful formulations,depending on the desired mode of application to the areas in whichsuppression of vegetation is desired. These formulations may contain aslittle as 0.1%, 0.2% or 0.5% to as much as 95% or more by weight of thetotal of the two herbicides.

The herbicidal compounds of use in the present invention can be in theform of a dispersible solution which comprises the herbicides dissolvedin a water-miscible solvent with the addition of a dispersing agent.

Alternatively, the composition can be in the form of water-soluble orwater-dispersible granules that disperse readily in water or otherdispersant. Water-soluble or water-dispersible granules normally areprepared to contain about 5-80% of the herbicides, depending on theabsorbency of the carrier, and usually also contain a wetting,dispersing or emulsifying agent to facilitate dispersion and may containa preservative. Typical carriers for water-soluble or water-dispersiblegranules include Fuller's earth, natural clays, silicas, and otherhighly absorbent, readily wet inorganic diluents. For example, a usefulwater-soluble or water-dispersible granule formulation contains 26.71parts of the herbicidal compounds, 30.90 parts of ammonium sulfate,30.89 parts of continental clay, 10.00 parts of sodium lignosulfonate asa dispersant, 1.00 part of sodium dioctylsuccinate as a wetting agentand 0.50 part of citric acid as a preservative. The mixture is milled,diluted with water to form a paste and the paste is extruded and driedto produce granules.

Other alternatives that may be employed are dusts which are free flowingadmixtures of the herbicides with finely divided solids such as talc,natural clays, kieselguhr, flours such as walnut shell and cottonseedflours, and other organic and inorganic solids which act as dispersantsand carriers for the herbicides. These finely divided solids have anaverage particle size of less than about 50 microns. A typical dustformulation useful herein is one containing 1.0 part or less of theherbicidal compounds and 99.0 parts of talc.

Also useful formulations for the herbicidal compounds of use in thepresent invention are wettable powders in the form of finely dividedparticles that disperse readily in water or other dispersant. Thewettable powder is ultimately applied to the locus where weed control isneeded either as a dry dust or as an emulsion in water or other liquid.Typical carriers for wettable powders include Fuller's earth, kaolinclays, silicas, and other highly absorbent, readily wet inorganicdiluents. Wettable powders are prepared to contain about 5-80% of theherbicides, depending on the absorbency of the carrier, and usually alsocontain a small amount of a wetting, dispersing or emulsifying agent tofacilitate dispersion. For example, a useful wettable powder formulationcontains 80.0 parts of the herbicidal compounds, 17.9 parts of Palmettoclay, and 1.0 part of sodium lignosulfonate and 0.3 part of sulfonatedaliphatic polyester as wetting agents. Additional wetting agents and/oroils will frequently be added to a tank mix to facilitate dispersion onthe foliage of the plant. Dry flowable formulations (DF) are usefulformulation for herbicidal compounds. A DF formulation can be preparedby forming a paste from a wettable powder by adding a liquid, forexample, water, then extruding the paste and drying to form smalldustless granules.

Other useful formulations for the herbicidal compounds of use in thepresent invention are emulsifiable concentrates (ECs) which arehomogeneous liquid compositions dispersible in water or otherdispersant, and may consist entirely of the herbicidal compounds and aliquid or solid emulsifying agent, or may also contain a liquid carrier,such as xylene, heavy aromatic naphthas, isophorone, or othernon-volatile organic solvents. For herbicidal application theseconcentrates are dispersed in water or other liquid carriers and appliedas a spray to the area to be treated. The percentage by weight of theherbicidal compounds may vary according to the manner in which thecomposition is to be applied, but in general comprises 0.5 to 95% of theherbicidal compounds by weight of the total composition.

Suspension concentrate (SC) formulations may also be employed. These aresimilar to ECs, except that the herbicidal compounds are suspended in aliquid carrier, generally water. Suspension concentrate formulations,like ECs, may include small amounts of surfactants, emulsifiers,stabilizers, thickeners, antifoam agents and/or preservatives and willtypically contain the herbicidal compounds in the range of 0.5 to 95%,frequently from 10 to 50%, by weight of the total composition. Forherbicidal application, SCs may be diluted in water or other liquidvehicle, and are normally applied as a spray to the area to be treated.

Other useful formulations include suspensions of the herbicidalcompounds in a relatively non-volatile solvent such as water, corn oil,kerosene, propylene glycol, or other suitable solvents.

Still other useful formulations for these herbicidal compositionsinclude simple solutions of the herbicides in a solvent in which it iscompletely soluble at the desired concentration, such as acetone,alkylated naphthalenes, xylene, or other organic solvents. Granularformulations, wherein the herbicides are carried on relative coarseparticles, are of particular utility for application to turf sites by aspreader for penetration of grass or can be used in combination with asolid fertilizer to combine nutrition and weed control. Pressurizedsprays, typically aerosols wherein the herbicides are dispersed infinely divided form as a result of vaporization of a low-boilingdispersant solvent carrier may also be used.

In some circumstances it may be desirable to combine two types offormulation e.g. one of the herbicidal compounds is used as anemulsifiable concentrate and the second herbicidal compound is dispersedas a powder in this concentrate.

The concentrate of the first and second herbicides (when used as thesole active components) in a composition for direct application to thelocus where control is desired by conventional ground methods ispreferably within the range of 0.001 to 10% by weight of thecomposition, especially 0.005 to 5% by weight, but more concentratedcompositions containing up to 40% may be desirable.

Typical wetting, dispersing or emulsifying agents that may be used inthe compositions of the present invention include, but are not limitedto, the alkyl and alkylaryl sulfonates and sulfates and their sodiumsalts; alkylaryl polyether alcohols; sulfated higher alcohols;polyethylene oxides; sulfonated animal and vegetable oils; sulfonatedpetroleum oils; fatty acid esters of polyhydric alcohols and theethylene oxide addition products of such esters; and the additionproduct of long-chain mercaptans and ethylene oxide. Many other types ofuseful surface-active agents are available in commerce. Surface-activeagents, when used, normally comprise 1 to 15% by weight of thecomposition.

In use on turf sites, the granular formulations, emulsifiableconcentrates, flowable concentrates, aqueous emulsions, solutions, etc.,may be diluted with water to give a concentration of the activeingredient in the range of 0.01% or 0.2% to 1.5% or 2.0%.

The following examples further illustrate the present invention, but, ofcourse, should not be construed as in any way limiting its scope. Theexamples include protocols for the evaluation of the compositions of thepresent invention in which a beneficial effect was observed. The testcompositions used were formulated pre-mixes or commercially availableformulations of the test compounds. The following commercially availableformulations were used: sulfentrazone, DISMISS™ Turf Herbicide from FMCCorporation; quinclorac, FACET® 75 DF herbicide or DRIVE® 75DF Herbicidefrom BASF Corporation, Inc.

A 75 DF formulation of sulfentrazone was prepared containing thefollowing: 81.6 parts of sulfentrazone technical (92% active), 4.0 partssodium diisopropyl naphthalene sulfonate, 12.0 parts lignosulfonatedispersants and 2.4 parts attaclay.

A mixture of sulfentrazone and quinclorac in a 1:3 ratio was prepared byblending together 60.02 grams of a 75 DF formulation of sulfentrazonewith 180.03 grams of Facet® 75 DF herbicide.

Example 1 Post-Emergent Herbicidal Evaluation of Sulfentrazone,Quinclorac and a One to Three Mixture of Sulfentrazone and Quinclorac on3 Leaf/2 Tiller Crabgrass, Violet, Clover and Plaintain

The compositions of the present invention were tested for herbicidalefficacy in the following manner:

The experimental design used randomized plots with post-emergenttreatment and three replications per test trial. The size of eachexperimental plot was 4 feet by 6 feet. The application of each testcomposition was performed with pressurized back-pack sprayers,calibrated to spray 200 gallons per acre. Test compositions containingsulfentrazone (DISMISS™ Turf Herbicide), quniclorac, (FACET® 75 DFherbicide) or a mixture of sulfentrazone and quinclorac in a 1:3 ratio,prepared as described above, were diluted with water to provide theappropriate test rate concentrations.

The control of weeds was evaluated in each experimental plot from 7 to41 days after treatment (DAT) of each test rate. The results, shown asan average of the replications, were compared with results observed inuntreated control plots in the same trials. The results are in Table 1below.

TABLE 1 Percent Control of Weeds in Turf Grass (three replications) Rateof Appln. Treatment (lb ai/acre) 7 DAT 14 DAT 21 DAT 28 DAT 41 DATSmooth Crabgrass (Digitaria ischaemum) A 0.57 70 78 86 75 71 B 0.75 7555 78 67 57 C 1.0 75 86 89 92 93 Control — 0 0 0 0 0 Field Violet (Violaarvensis) A 0.57 64 75 76 70 75 B 0.75 43 46 43 41 37 C 1.0 76 71 72 8989 Control — 0 0 0 0 0 White Clover (Trifolium repens) A 0.57 59 63 5952 — B 0.75 50 50 50 63 — C 1.0 63 79 100 89 — Control — 0 0 0 0 —Yellow Nutsedge (Cyperus esculentus) A 0.57 50 75 89 91 — B 0.75 100 4010 13 — C 1.0 95 100 100 100 — Control — 0 0 0 0 — Blackseed Plantain(Plantago rugelii) A 0.57 83 88 100 100 — B 0.75 100 100 100 100 — C 1.0100 100 100 100 — Control — 0 0 0 0 — Highlighted numbers indicateadvantageous herbicidal properties. A = sulfentrazone, DISMISS ™ TurfHerbicide available from FMC Corporation B = quinclorac, FACET ® 75 DFherbicide from BASF Corporation, Inc. C = sulfentrazone/quinclorac 1:3ratio (1.0 lb/acre = 0.25 lb/acre sulfentrazone, 0.75 lb/acrequinclorac)

Example 2 Post-Emergent Herbicidal Evaluation of Sulfentrazone,Quinclorac and a One to Three Mixture of Sulfentrazone and Quinclorac onTillered Crabgrass, Violet, Clover, Nutsedge and Plaintain

The compositions of the present invention were tested for herbicidalefficacy in the following manner:

The experimental design used randomized plots with post-emergenttreatment and three replications per test trial. The size of eachexperimental plot was 4 feet by 6 feet. The application of each testcomposition was performed with pressurized back-pack sprayers,calibrated to spray 200 gallons per acre. Test compositions containingsulfentrazone (DISMISS™ Turf Herbicide), quinclorac, (FACET® 75 DFherbicide) or a mixture of sulfentrazone and quinclorac in a one tothree ratio, prepared as described above, were diluted with water toprovide the appropriate test rate concentrations.

The control of weeds was evaluated in each experimental plot from 1 to27 days after treatment (DAT) of each test rate. The results, shown asan average of the replications, were compared with results observed inuntreated control plots in the same trials. The results are in Table 2below.

TABLE 2 Percent Control of Weeds in Turf Grass (three replications) Rateof Appln. Treatment (lb ai/acre) 7 DAT 14 DAT 21 DAT Smooth Crabgrass(Digitaria ischaemum) A 0.57 34 36 52 B 0.75 54 66 67 C 1.0  80 85 88Control — 0 0 0 Field Violet (Viola arvensis) A 0.57 66 78 69 B 0.75 4648 51 C 1.0  66 91 89 Control — 0 0 0 White Clover (Trifolium repens) A0.57 45 74 68 B 0.75 60 87 82 C 1.0  66 96 96 Control — 0 0 0 YellowNutsedge (Cyperus esculentus) A 0.57 100 100 100 B 0.75 83 54 37 C 1.0 100 100 100 Control — 0 0 0 Blackseed Plantain (Plantago rugelii) A 0.57100 100 100 B 0.75 83 100 100 C 1.0  100 100 100 Control — 0 0 0Highlighted numbers indicate advantageous herbicidal properties. A =sulfentrazone, DISMISS ™ Turf Herbicide available from FMC Corporation B= quinclorac, FACET ® 75 DF herbicide from BASF Corporation, Inc. C =sulfentrazone/quinclorac 1:3 ratio (1.0 lb/acre = 0.25 lb/acresulfentrazone, 0.75 lb/acre quinclorac)

Example 3 Post-Emergent Herbicidal Evaluation of Sulfentrazone,Quinclorac and a One to Three Mixture of Sulfentrazone and Quinclorac onCrabgrass and Yellow Nutsedge

The compositions of the present invention were tested for herbicidalefficacy in the following manner:

Test compositions containing sulfentrazone (DISMISS™ Turf Herbicide),quniclorac, (DRIVE® 75 DF Herbicide) or mixture of sulfentrazone andquinclorac in a three to one ratio, prepared as described above, werediluted with water to provide the appropriate test rate concentrations.A nonionic surfactant (0.25%) was added to each test solution.

The test weeds include Red River crabgrass (Digitaria ciliaris) andyellow nutsedge (Cyperus esculentusi).

For post-emergence testing, three disposable 3 inch square pots for eachrate of application of each herbicide were filled with a soil, comprisedof peat moss, vermiculite, bark ash, pine bark, limestone and a wettingagent, to which 8 to 10 seeds were planted. The pots were placed in agreenhouse and watered daily, thus allowing the seeds to germinate andthe foliage to develop.

Pots designated for treatment were placed on a conveyor belt and theconveyor belt fed under a spray nozzle mounted about ten inches abovethe foliage. The spray of herbicidal solution was commenced and oncestabilized; the pots were passed under the spray at a speed to receive acoverage equivalent of 30 gallons per acre. The application rates arethose shown in Table 3 below for the individual herbicidal solutions andthe mixture of sulfentrazone and quinclorac. The post-emergence potswere immediately placed in the green-house and not watered until 24hours after treatment with the test solution. Thereafter they wereregularly watered at ground level. The control of weeds was evaluated ineach experimental test from 1 to 22 days after treatment (DAT). Theresults, shown as an average of the replications, were compared withresults observed in untreated control pots in the same tests. Theresults are in Table 3 below.

Percent control was determined by a method similar to the 0 to 100rating system disclosed in “Research Methods in Weed Science,” 2nd ed.,B. Truelove, Ed.; Southern Weed Science Society; Auburn University,Auburn, Ala., 1977. The rating system is as follows:

Herbicide Rating System Rating Description of Main Percent ControlCategories Weed Description 0 No Effect No weed control 10 Very poorweed control 20 Slight Effect Poor weed control 30 Poor to deficientweed control 40 Deficient weed control 50 Moderate Effect Deficient tomoderate weed control 60 Moderate weed control 70 Control somewhat lessthan satisfactory 80 Severe Satisfactory to good weed control 90 Verygood to excellent weed control 100 Complete Effect Complete weeddestruction

TABLE 3 Percent Control of Red River Crabgrass (Digitaria ciliaris) andYellow Nutsedge (Cyperus esculentusi) (three replications) Rate ofAppln. Treatment (lb ai/acre) 1 DAT 3 DAT 7 DAT 14 DAT 21 DAT Red RiverCrabgrass Treated at 1-2 leaf stage, 11 days old A 0.375 50 70 50 20 10A 0.25 60 70 50 20 5 A 0.125 50 60 50 40 30 B 1.0 0 10 10 2 2 B 0.75 010 5 0 0 B 0.375 0 5 5 0 0 C 1.5 50 70 75 80 80 C 1.25 50 70 75 72 75 C1.0 47 60 70 67 74 C 0.75 60 60 75 70 70 C 0.375 53 60 50 43 40 Control— 0 0 0 0 0 Red River Crabgrass Treated at 3-4 leaf stage, 1-2 tillers,14 days old A 0.375 20 20 22 0 0 A 0.25 25 25 30 12 5 A 0.125 25 25 3010 5 B 1.0 0 5 10 5 5 B 0.75 0 5 5 5 0 B 0.375 0 5 5 0 0 C 1.5 20 60 7577 75 C 1.25 20 60 75 72 75 C 1.0 15 60 75 70 60 C 0.75 15 60 70 63 60 C0.375 20 60 70 67 50 Control — 0 0 0 0 0 Yellow Nutsedge, Treated at 1-5leaf stage, 7 days old A 0.375 75 91 95 73 70 A 0.25 70 85 77 68 50 A0.125 50 50 63 70 67 B 1.0 0 0 0 0 0 B 0.75 0 0 0 0 0 B 0.375 0 0 0 0 0C 1.5 40 94 98 90 85 C 1.25 40 85 96 95 80 C 1.0 40 77 80 87 80 C 0.7550 88 87 77 70 C 0.375 40 87 82 63 70 Control — 0 0 0 0 0 YellowNutsedge Treated at 5-7 leaves, cut to 6 cm tall, 28 days old A 0.375 090 90 90 90 A 0.25 0 75 80 80 90 A 0.125 0 80 85 70 60 B 1.0 0 5 5 5 0 B0.75 0 0 2 2 0 B 0.375 0 5 5 5 0 C 1.5 0 80 85 85 50 C 1.25 0 80 85 8590 C 1.0 0 70 90 90 90 C 0.75 0 70 90 90 90 C 0.375 0 70 90 70 70Control — 0 0 0 0 Highlighted numbers indicate advantageous herbicidalproperties. A = sulfentrazone, DISMISS ™ Turf Herbicide available fromFMC Corporation B = quinclorac, DRIVE ® 75 DF herbicide from BASFCorporation, Inc. C = sulfentrazone/quinclorac 1:3 ratio (1.0 lb/acre =0.25 lb/acre sulfentrazone, 0.75 lb/acre quinclorac)

Example 4 Post-Emergent Herbicidal Evaluation of Sulfentrazone,Quinclorac and Mixtures of Sulfentrazone and Quinclorac

The compositions of the present invention were tested for herbicidalefficacy in the following manner:

Test compositions containing sulfentrazone (75 DF formulation),quniclorac, (DRIVE® 75 DF Herbicide) or mixtures of sulfentrazone andquinclorac at ratios of 1:1 to 1:5, were diluted with water to providethe appropriate test rate concentrations. A nonionic surfactant (0.25%)was added to each test solution. The test weeds include crabgrass(Digitaria sp), Chickweed (Stellaria media), Hemp Sesbania (Sesbaniaexaltata), Kochia (Kochia scoparia), Ivyleaf Morningglory (Ipomoeahederacea), Redroot Pigweed (Amaranthus retroflexus) and yellow nutsedge(Cyperus esculentusi).

For post-emergence testing, three disposable 3 inch square pots for eachrate of application of each herbicide were filled with a soil, comprisedof peat moss, vermiculite, bark ash, pine bark, limestone and a wettingagent, to which 8 to 10 seeds were planted. The pots were placed in agreenhouse and watered daily, thus allowing the seeds to germinate andthe foliage to develop for 22 days, 3 months for Kochia.

Pots designated for treatment were placed on a conveyor belt and theconveyor belt fed under a spray nozzle mounted about ten inches abovethe foliage. The spray of herbicidal solution was commenced and oncestabilized; the pots were passed under the spray at a speed to receive acoverage equivalent of 30 gallons per acre. The application rates arethose shown in Table 4 below for the individual herbicidal solutions andthe mixture of sulfentrazone and quinclorac. The post-emergence potswere immediately placed in the green-house and not watered until 24hours after treatment with the test solution. Thereafter they wereregularly watered at ground level. The control of weeds was evaluated ineach experimental test from 2 to 20 days after treatment (DAT). Theresults, shown as an average of the replications, were compared withresults observed in untreated control pots in the same tests. Theresults are in Table 4 below.

Percent control was determined by a method similar to the 0 to 100rating system disclosed in “Research Methods in Weed Science,” 2nd ed.,B. Truelove, Ed.; Southern Weed Science Society; Auburn University,Auburn, Ala., 1977. The rating system is as follows:

Herbicide Rating System Rating Description of Main Percent ControlCategories Weed Description 0 No Effect No weed control 10 Very poorweed control 20 Slight Effect Poor weed control 30 Poor to deficientweed control 40 Deficient weed control 50 Moderate Effect Deficient tomoderate weed control 60 Moderate weed control 70 Control somewhat lessthan satisfactory 80 Severe Satisfactory to good weed control 90 Verygood to excellent weed control 100 Complete Effect Complete weeddestruction

TABLE 4 Post-emergent Herbicidal Evaluation of Sulfentrazone, Quincloracand Mixtures Thereof Rate of application Treatment (lb ai/acre) 2 DAT 7DAT 14 DAT 20 DAT Crabgrass A 0.25 10 10 5 5 B 0.25 10 20 20 10 B 0.5 010 60 50 B 0.75 0 0 60 50 B 1.0 0 10 60 70 B 1.25 0 10 60 70 A/B0.25/0.25 10 10 10 10 A/B 0.25/0.5  10 10 70 60 A/B 0.25/0.75 15 10 7560 A/B 0.25/1.0  10 10 70 75 A/B 0.25/1.25 10 10 75 80 Control 0 0 0 0 0Chickweed A 0.25 30 30 10 0 B 0.25 0 0 0 0 B 0.5 0 0 0 0 B 0.75 0 0 0 0B 1.0 0 5 5 5 B 1.25 5 5 2 5 A/B 0.25/0.25 10 40 50 20 A/B 0.25/0.5  1060 60 60 A/B 0.25/0.75 15 40 50 50 A/B 0.25/1.0  10 40 50 50 A/B0.25/1.25 10 40 60 40 Control 0 0 0 0 0 Hemp Sesbania A 0.25 70 85 90 90B 0.25 0 0 5 20 B 0.5 0 10 20 60 B 0.75 0 0 10 60 B 1.0 10 10 20 60 B1.25 0 0 10 50 A/B 0.25/0.25 75 75 90 95 A/B 0.25/0.5  70 75 99 99 A/B0.25/0.75 60 60 90 90 A/B 0.25/1.0  50 60 95 99 A/B 0.25/1.25 50 70 9599 Control 0 0 0 0 0 Kochia A 0.25 10 70 95 99 B 0.25 0 0 5 5 B 0.5 0 020 20 B 0.75 0 0 10 5 B 1.0 0 0 10 20 B 1.25 0 0 10 10 A/B 0.25/0.25 1085 100 100 A/B 0.25/0.5  10 75 99 100 A/B 0.25/0.75 10 75 99 100 A/B0.25/1.0  10 50 90 100 A/B 0.25/1.25 10 70 99 100 Control 0 0 0 0 0Ivyleaf Morningglory A 0.25 60 80 90 99 B 0.25 20 25 60 70 B 0.5 20 2540 50 B 0.75 20 25 40 50 B 1.0 20 25 50 70 B 1.25 20 25 40 50 A/B0.25/0.25 70 95 99 100 A/B 0.25/0.5  80 100 100 100 A/B 0.25/0.75 70 100100 100 A/B 0.25/1.0  60 95 100 100 A/B 0.25/1.25 60 100 100 100 Control0 0 0 0 0 Redroot Pigweed A 0.25 80 95 99 90 B 0.25 10 10 10 10 B 0.5 00 0 0 B 0.75 0 0 0 0 B 1.0 0 0 0 0 B 1.25 10 10 10 10 A/B 0.25/0.25 8095 99 95 A/B 0.25/0.5  80 100 100 100 A/B 0.25/0.75 50 99 100 100 A/B0.25/1.0  70 100 100 95 A/B 0.25/1.25 70 100 100 100 Control 0 0 0 0 0Yellow Nutsedge A 0.25 25 60 85 95 B 0.25 0 0 0 0 B 0.5 0 0 0 0 B 0.75 00 0 0 B 1.0 0 0 0 0 B 1.25 0 0 0 0 A/B 0.25/0.25 25 75 90 90 A/B0.25/0.5  30 60 80 99 A/B 0.25/0.75 20 70 90 95 A/B 0.25/1.0  30 50 7590 A/B 0.25/1.25 30 60 85 95 Control 0 0 0 0 0 Highlighted numbersindicate advantageous herbicidal properties. A = sulfentrazone, 75 DFformulation. B = quinclorac, DRIVE ® 75 DF herbicide from BASFCorporation, Inc.

Those of ordinary skill in the art will appreciate that variations ofthe invention may be used and that it is intended that the invention maybe practiced otherwise than as specifically described herein.Accordingly, this invention includes all modifications encompassedwithin the spirit and scope of the invention as defined by the followingclaims.

What is claimed is:
 1. A method for post-emergence control of weeds in aturf site wherein the weeds are selected from the group consisting ofclover, nutsedge, violet, chickweed, sesbania, kochia, morningglory andpigweed, said method comprising applying a composition comprising amixture of sulfentrazone and quinclorac in a ratio of from 1:5 to 1:1,at a rate of from 0.375 pound of sulfentrazone and quinclorac/acre to1.5 pounds of sulfentrazone and quinclorac/acre, provided that theamount of sulfentrazone applied is equal to at least 0.09 lb/acre. 2.The method of claim 1 wherein the ratio of sulfentrazone to quincloracis 1:3.
 3. The method of claim 2 wherein the mixture of sulfentrazoneand quinclorac is applied at a rate of from 0.75 pound of sulfentrazoneand quinclorac/acre to 1.25 pounds of sulfentrazone and quinclorac/acre.4. The method of claim 1 whereby the mixture provides extended durationof control over said weeds compared with applying the individualcomponents of the mixture to said weeds.
 5. The method of claim 4wherein the method provides extended duration of control for at least 14days after treatment.
 6. The method of claim 5 wherein the weed isclover and wherein extended duration of control comprises control ofclover for at least 21 days after treatment.